Children who spend too long playing with Christmas computer game presents this year could end up with "Nintendo thumb" or other injuries, a charity has said.

Others who spend time bent over personal computers surfing the Internet for hours could face years of agony from bad posture and repetitive strain injury (RSI), according to specialists.

I have seen everything from Nintendo thumb to pains in the shoulders and swollen joints

Bunny Martin, Body Action Campaign

It is estimated that three million Nintendo and Sony games systems were given as presents over the festive season.

But some children are developing signs of RSI, particularly in their thumbs, as they play the games for hours.

These sorts of injuries occur from repeated physical movements and can result in damage to tendons, nerves and muscles.

Campaign

The charity Body Action Campaign, which was launched to combat the problem, wants schools to issue advice to children on how to avoid problems.

It has been visiting schools to highlight the problem over the last year.

The Playstation is a big-selling console

Physiotherapist Wendy Emberson examined children who played the games regularly and is said to have found thumb injuries in 15% of them, and bad posture in almost all of them.

Bunny Martin, founder of the Body Action Campaign, said: "The Government wants every child at school to have a computer by 2001 - but it has not put money aside to help them overcome risks to their health.

"I have seen everything from Nintendo thumb to pains in the shoulders and swollen joints.

"Children will be using computers all their lives and must be thought how to use them safely and avoid problems."

British trades union officials estimate that 5.5 million working days are lost every year to upper limb disorders such as RSI and more than 100,000 new medical cases are being reported each year.

The Trades Union Congress is to publish the results of a survey on back strains and RSI in the workplace on Tuesday.